Van-der-Waals integration of superconducting tunneling devices

QUEST Center event
No
Speaker
Hadar Steinberg (Hebrew University)
Date
11/01/2018 - 14:30Add to Calendar 2018-01-11 14:30:00 2018-01-11 14:30:00 Van-der-Waals integration of superconducting tunneling devices Layered materials can be exfoliated to very thin films. In our group we utilize a technique called “mechanical transfer”, which allows stacking of such materials into new types of heterostructures which can involve layers of distinct functionalities. In my talk I will describe this fabrication technique, and demonstrate how we build a new type of device which consists of a layered superconductor (NbSe2), on which we deposit an ultra-thin layer of the semiconductor WSe2. Together, these two materials form a tunneling device, which can be cooled to extremely low temperatures (20 mK) in a dilution cryostat fitted with special filters which allow very sensitive energy spectroscopy. Our tunneling spectra allow tracking the evolution of the superconductor order parameter at the presence of strong magnetic fields, and quantifying its stability. Specifically, the depairing energy scale can be evaluated, and its origin – orbital or spin – identified. Thus, we are able to identify which of the two bands participating in NbSe2 superconductivity is associated with this material’s remarkable stability against in-plane magnetic field.   Resnick (#209) - room 210 המחלקה לפיזיקה physics.dept@mail.biu.ac.il Asia/Jerusalem public
Place
Resnick (#209) - room 210
Abstract

Layered materials can be exfoliated to very thin films. In our group we utilize a technique called “mechanical transfer”, which allows stacking of such materials into new types of heterostructures which can involve layers of distinct functionalities. In my talk I will describe this fabrication technique, and demonstrate how we build a new type of device which consists of a layered superconductor (NbSe2), on which we deposit an ultra-thin layer of the semiconductor WSe2. Together, these two materials form a tunneling device, which can be cooled to extremely low temperatures (20 mK) in a dilution cryostat fitted with special filters which allow very sensitive energy spectroscopy. Our tunneling spectra allow tracking the evolution of the superconductor order parameter at the presence of strong magnetic fields, and quantifying its stability. Specifically, the depairing energy scale can be evaluated, and its origin – orbital or spin – identified. Thus, we are able to identify which of the two bands participating in NbSe2 superconductivity is associated with this material’s remarkable stability against in-plane magnetic field.

 

תאריך עדכון אחרון : 24/12/2017